src/bin/lttng/commands/stop.c

   1 /*
   2  * Copyright (C) 2011 - David Goulet <david.goulet@polymtl.ca>
   3  *
   4  * This program is free software; you can redistribute it and/or modify
   5  * it under the terms of the GNU General Public License, version 2 only,
   6  * as published by the Free Software Foundation.
   7  *
   8  * This program is distributed in the hope that it will be useful,
   9  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  10  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  11  * GNU General Public License for more details.
  12  *
  13  * You should have received a copy of the GNU General Public License along
  14  * with this program; if not, write to the Free Software Foundation, Inc.,
  15  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
  16  */
  17
  18 #define _LGPL_SOURCE
  19 #include <popt.h>
  20 #include <stdio.h>
  21 #include <stdlib.h>
  22 #include <string.h>
  23 #include <sys/stat.h>
  24 #include <sys/types.h>
  25 #include <unistd.h>
  26 #include <assert.h>
  27
  28 #include <common/sessiond-comm/sessiond-comm.h>
  29 #include <common/mi-lttng.h>
  30
  31 #include "../command.h"
  32
  33 static char *opt_session_name;
  34 static int opt_no_wait;
  35 static struct mi_writer *writer;
  36
  37 #ifdef LTTNG_EMBED_HELP
  38 static const char help_msg[] =
  39 #include <lttng-stop.1.h>
  40 ;
  41 #endif
  42
  43 enum {
  44         OPT_HELP = 1,
  45         OPT_LIST_OPTIONS,
  46 };
  47
  48 static struct poptOption long_options[] = {
  49         /* longName, shortName, argInfo, argPtr, value, descrip, argDesc */
  50         {"help",      'h', POPT_ARG_NONE, 0, OPT_HELP, 0, 0},
  51         {"list-options", 0, POPT_ARG_NONE, NULL, OPT_LIST_OPTIONS, NULL, NULL},
  52         {"no-wait",   'n', POPT_ARG_VAL, &opt_no_wait, 1, 0, 0},
  53         {0, 0, 0, 0, 0, 0, 0}
  54 };
  55
  56 /*
  57  * Mi print of partial session
  58  */
  59 static int mi_print_session(char *session_name, int enabled)
  60 {
  61         int ret;
  62         assert(writer);
  63         assert(session_name);
  64
  65         /* Open session element */
  66         ret = mi_lttng_writer_open_element(writer, config_element_session);
  67         if (ret) {
  68                 goto end;
  69         }
  70
  71         /* Print session name element */
  72         ret = mi_lttng_writer_write_element_string(writer, config_element_name,
  73                         session_name);
  74         if (ret) {
  75                 goto end;
  76         }
  77
  78         /* Is enabled ? */
  79         ret = mi_lttng_writer_write_element_bool(writer, config_element_enabled,
  80                         enabled);
  81         if (ret) {
  82                 goto end;
  83         }
  84
  85         /* Close session element */
  86         ret = mi_lttng_writer_close_element(writer);
  87
  88 end:
  89         return ret;
  90 }
  91
  92 /*
  93  * Start tracing for all trace of the session.
  94  */
  95 static int stop_tracing(void)
  96 {
  97         int ret;
  98         char *session_name;
  99
 100         if (opt_session_name == NULL) {
 101                 session_name = get_session_name();
 102                 if (session_name == NULL) {
 103                         ret = CMD_ERROR;
 104                         goto error;
 105                 }
 106         } else {
 107                 session_name = opt_session_name;
 108         }
 109
 110         ret = lttng_stop_tracing_no_wait(session_name);
 111         if (ret < 0) {
 112                 switch (-ret) {
 113                 case LTTNG_ERR_TRACE_ALREADY_STOPPED:
 114                         WARN("Tracing already stopped for session %s", session_name);
 115                         break;
 116                 default:
 117                         ERR("%s", lttng_strerror(ret));
 118                         break;
 119                 }
 120                 goto free_name;
 121         }
 122
 123         if (!opt_no_wait) {
 124                 _MSG("Waiting for data availability");
 125                 fflush(stdout);
 126                 do {
 127                         ret = lttng_data_pending(session_name);
 128                         if (ret < 0) {
 129                                 /* Return the data available call error. */
 130                                 goto free_name;
 131                         }
 132
 133                         /*
 134                          * Data sleep time before retrying (in usec). Don't sleep if the call
 135                          * returned value indicates availability.
 136                          */
 137                         if (ret) {
 138                                 usleep(DEFAULT_DATA_AVAILABILITY_WAIT_TIME_US);
 139                                 _MSG(".");
 140                                 fflush(stdout);
 141                         }
 142                 } while (ret != 0);
 143                 MSG("");
 144         }
 145
 146         ret = CMD_SUCCESS;
 147
 148         print_session_stats(session_name);
 149         MSG("Tracing stopped for session %s", session_name);
 150         if (lttng_opt_mi) {
 151                 ret = mi_print_session(session_name, 0);
 152                 if (ret) {
 153                         goto free_name;
 154                 }
 155         }
 156
 157 free_name:
 158         if (opt_session_name == NULL) {
 159                 free(session_name);
 160         }
 161
 162 error:
 163         return ret;
 164 }
 165
 166 /*
 167  *  cmd_stop
 168  *
 169  *  The 'stop <options>' first level command
 170  */
 171 int cmd_stop(int argc, const char **argv)
 172 {
 173         int opt, ret = CMD_SUCCESS, command_ret = CMD_SUCCESS, success = 1;
 174         static poptContext pc;
 175         const char *leftover = NULL;
 176
 177         pc = poptGetContext(NULL, argc, argv, long_options, 0);
 178         poptReadDefaultConfig(pc, 0);
 179
 180         while ((opt = poptGetNextOpt(pc)) != -1) {
 181                 switch (opt) {
 182                 case OPT_HELP:
 183                         SHOW_HELP();
 184                         goto end;
 185                 case OPT_LIST_OPTIONS:
 186                         list_cmd_options(stdout, long_options);
 187                         goto end;
 188                 default:
 189                         ret = CMD_UNDEFINED;
 190                         goto end;
 191                 }
 192         }
 193
 194         /* Mi check */
 195         if (lttng_opt_mi) {
 196                 writer = mi_lttng_writer_create(fileno(stdout), lttng_opt_mi);
 197                 if (!writer) {
 198                         ret = -LTTNG_ERR_NOMEM;
 199                         goto end;
 200                 }
 201
 202                 /* Open command element */
 203                 ret = mi_lttng_writer_command_open(writer,
 204                                 mi_lttng_element_command_stop);
 205                 if (ret) {
 206                         ret = CMD_ERROR;
 207                         goto end;
 208                 }
 209
 210                 /* Open output element */
 211                 ret = mi_lttng_writer_open_element(writer,
 212                                 mi_lttng_element_command_output);
 213                 if (ret) {
 214                         ret = CMD_ERROR;
 215                         goto end;
 216                 }
 217
 218                 /*
 219                  * Open sessions element
 220                  * For validation
 221                  */
 222                 ret = mi_lttng_writer_open_element(writer,
 223                                 config_element_sessions);
 224                 if (ret) {
 225                         ret = CMD_ERROR;
 226                         goto end;
 227                 }
 228         }
 229
 230         opt_session_name = (char*) poptGetArg(pc);
 231
 232         leftover = poptGetArg(pc);
 233         if (leftover) {
 234                 ERR("Unknown argument: %s", leftover);
 235                 ret = CMD_ERROR;
 236                 goto end;
 237         }
 238
 239         command_ret = stop_tracing();
 240         if (command_ret) {
 241                 success = 0;
 242         }
 243
 244         /* Mi closing */
 245         if (lttng_opt_mi) {
 246                 /* Close sessions and  output element */
 247                 ret = mi_lttng_close_multi_element(writer, 2);
 248                 if (ret) {
 249                         ret = CMD_ERROR;
 250                         goto end;
 251                 }
 252
 253                 /* Success ? */
 254                 ret = mi_lttng_writer_write_element_bool(writer,
 255                                 mi_lttng_element_command_success, success);
 256                 if (ret) {
 257                         ret = CMD_ERROR;
 258                         goto end;
 259                 }
 260
 261                 /* Command element close */
 262                 ret = mi_lttng_writer_command_close(writer);
 263                 if (ret) {
 264                         ret = CMD_ERROR;
 265                         goto end;
 266                 }
 267         }
 268
 269 end:
 270         /* Mi clean-up */
 271         if (writer && mi_lttng_writer_destroy(writer)) {
 272                 /* Preserve original error code */
 273                 ret = ret ? ret : -LTTNG_ERR_MI_IO_FAIL;
 274         }
 275
 276         /* Overwrite ret if an error occurred in stop_tracing() */
 277         ret = command_ret ? command_ret : ret;
 278
 279         poptFreeContext(pc);
 280         return ret;
 281 }